This invention relates to apparatus and method for controlling the amount of air required upon start of internal combustion engines.
An apparatus for controlling the amount of air required for an internal combustion engine from engine start until termination of warm-up operation is well known as a so-called idle speed control apparatus which is disclosed in U.S. Pat. No. 3,964,457.
In this idle speed control apparatus, target values of engine revolution corresponding to cooling water temperatures are stored in a function generator, and a value representative of an actual revolution of the internal combustion engine is compared with a target value derived from the function generator to control the amount of air being supplied to the internal combustion engine so that the actual engine revolution can be converged to the target revolution.
In addition, the controlling function of such an idle speed control apparatus is deactivated upon start especially cranking of the internal combustion engine and in this case, an air control mechanism is activated so that a maximum amount of air required for engine start can be supplied to the internal combustion engine.
The maximum air amount is however definitely set irrespective of temperatures of the internal combustion engine and hence the same amount of air is supplied to the internal combustion engine even under conditions of different engine temperatures, thus adversely affecting the internal combustion engine.
An object of this invention is to provide apparatus and method for controlling air amount upon engine start which can supply amounts of air required upon engine start in accordance with temperatures of an internal combustion engine.
This invention is featured in that a control signal generator is provided which provide control signals indicative of amounts of air required upon engine start and corresponding to temperatures of an internal combustion engine, and an amount of air required upon engine start is derived from the control signal generator in accordance with an engine temperature upon the engine start to control air amount thereupon.